Shaft coupling

Abstract

A shaft coupling is disclosed herein. The shaft coupling includes a tubular portion extending along a central axis. The tubular portion has a maximum inner diameter. The shaft coupling also includes a first set of internal splines positioned in the tubular portion. The shaft coupling also includes a dam rising above the maximum inner diameter in the tubular portion. The dam is spaced from the first set of internal splines along the central axis. The shaft coupling also includes at least one aperture for receiving lubricant for the first set of internal splines. The at least one aperture extends through the tubular portion along an aperture axis transverse to the central axis. A cross-sectional area of the at least one aperture decreases along at least part of the aperture axis. In another feature, the shaft coupling can include a passageway extending through the dam.

What is claimed is: 
     
       1. A shaft coupling comprising:
 a tubular portion extending along a central axis and having an outer surface and a hollow interior, said hollow interior defining a maximum inner diameter; 
 a first set of internal splines positioned in said tubular portion; 
 a dam extending radially inward from an inner surface of said tubular portion and into said hollow interior, said dam defining a radial top surface positioned inwardly beyond said maximum inner diameter of said tubular portion and said dam spaced from said first set of internal splines along said central axis; and 
 at least one aperture for receiving lubricant for said first set of internal splines and extending from said outer surface of said tubular portion to said hollow interior, said at least one aperture arranged along an aperture axis transverse to said central axis, wherein a cross-sectional area of said at least one aperture decreases along at least part of said aperture axis, wherein said at least one aperture extends between an entry port positioned at said outer surface of said tubular portion and an exit portion opening into said hollow interior, said entry port being larger than said exit port. 
 
     
     
       2. The shaft coupling of  claim 1  wherein said at least one aperture is further defined as wedge-shaped in at least one plane normal to said central axis. 
     
     
       3. The shaft coupling of  claim 1  wherein said cross-sectional area of said at least one aperture progressively decreases along a majority of a length of said aperture axis. 
     
     
       4. The shaft coupling of  claim 1  wherein said aperture axis is further defined as perpendicular to said central axis. 
     
     
       5. The shaft coupling of  claim 1  wherein said at least one aperture is further defined as extending from said outer surface of said tubular portion to said radial top surface of said dam. 
     
     
       6. The shaft coupling of  claim 1  further comprising: a second set of internal splines positioned in said tubular portion such that said dam and said at least one aperture are positioned between said first and second sets of splines along said central axis. 
     
     
       7. The shaft coupling of  claim 1  further comprising:
 a central passageway extending axially through a central portion of said dam with said at least one aperture in communication with said central passageway; and 
 at least one additional passageway extending axially through said dam and radially offset from said central passageway, said at least one additional passageway being smaller in size than said central passageway. 
 
     
     
       8. The shaft coupling of  claim 7  further comprising a plurality of said at least one additional passageway extending through said dam. 
     
     
       9. The shaft coupling of  claim 7  wherein said at least one additional passageway extending through said dam is positioned between said radial top surface of said dam and said inner surface of said tubular portion. 
     
     
       10. The shaft coupling of  claim 1  further comprising a central passageway extending axially through a central portion of said dam with said at least one aperture in communication with said central passageway. 
     
     
       11. The shaft coupling of  claim 10  further comprising at least one additional passageway extending axially through said dam and radially offset from said central passageway. 
     
     
       12. The shaft coupling of  claim 11  wherein said at least one additional passageway is positioned between said radial top surface of said dam and said inner surface of said tubular portion to pass lubricant through said dam. 
     
     
       13. The shaft coupling of  claim 12  wherein said at least one additional passageway is smaller in size than said central passageway. 
     
     
       14. The shaft coupling of  claim 11  further comprising a plurality of said at least one additional passageway extending through said dam. 
     
     
       15. The shaft coupling of  claim 1  further comprising at least one passageway extending axially through said dam and radially offset from said central axis of said tubular portion. 
     
     
       16. The shaft coupling of  claim 15  wherein said at least one passageway is positioned between said radial top surface of said dam and said inner surface of said tubular portion to pass lubricant through said dam. 
     
     
       17. A shaft coupling comprising:
 a tubular portion extending along a central axis and having an outer surface and a hollow interior, said hollow interior defining a maximum inner diameter; 
 first and second sets of internal splines positioned in said tubular portion and spaced from one another along said central axis; 
 a dam extending radially inward from an inner surface of said tubular portion and into said hollow interior, said dam defining a radial top surface positioned inwardly beyond said maximum inner diameter in said tubular portion and said dam positioned between said first and second sets of internal splines along said central axis; 
 at least one aperture for receiving lubricant for said first and second sets of internal splines, said at least one aperture extending from said outer surface of said tubular portion to said hollow interior, said at least one aperture arranged along an aperture axis transverse to said central axis; and 
 a central passageway extending axially through a central portion of said dam with said at least one aperture in communication with said central passageway, and at least one additional passageway extending axially through said dam and radially offset from said central passageway and positioned between said radial top surface of said dam and said inner surface of said tubular portion to pass lubricant through said dam, said at least one additional passageway being smaller in size than said central passageway. 
 
     
     
       18. The shaft coupling of  claim 17  wherein said at least one aperture includes a plurality of apertures extending from said outer surface of said tubular portion to said hollow interior, and said at least one additional passageway includes a plurality of additional passageways extending through said dam, said apertures and additional passageways being positioned in an alternating arrangement circumferentially about said central axis. 
     
     
       19. The shaft coupling of  claim 17  wherein said at least one aperture extends between an entry port positioned at said outer surface of said tubular portion and an exit port positioned on said dam, said entry port being larger than said exit port. 
     
     
       20. The shaft coupling of  claim 17  wherein a cross-sectional area of said at least one aperture decreases along at least part of said aperture axis.